Non-competes, anti-moonlighting clauses, and contract employment are all quite common and have been for a long time. The "legal implication" is that you read the contracts and follow it or work around it. Most corporate/employment lawyers, HR teams, or hiring managers should be fairly familiar with these situations.
Also, the demands listed in employment agreements are not always legally enforceable, or not legally enforceable in as broad of a way that they appear to be phrased.
Also, the demands listed in employment agreements are not always legally enforceable, or not legally enforceable in as broad of a way that they appear to be phrased.